(1) Field of the Invention
The present invention relates to ceramics containing tetragonal zirconia.
(2) Related Art Statement
Ceramics containing tetragonal zirconia have been heretofore widely studied as a high temperature structural material, a material for use in cutting tools, oxygen sensors and so on, since such ceramics have thermal resistance, high strength and high toughness, in addition to ion conductivity at high temperatures.
While zirconia is stable at high temperatures as the high density tetragonal system, it is stable at low temperatures as the low density monoclinic system. Therefore, zirconia undergoes phase transformation when the temperature varies, resulting in large volumetric changes.